Data crossing between multiple systems

@dellmation  The HDMI ports are purely inputs and only receive video and audio. They don't receive any other type of data, nor do they send any data back to the source system.  Technically HDMI ports can be used to send audio back to a source (this is called ARC) and can be used for 100 Mb Ethernet, but I've never seen any Dell display or even PC that supports either of those capabilities.  ARC is typically used to send audio from a Smart TV down to an AV receiver, and I've never come across HDMI Ethernet in the wild.

If you were worried about USB data or something, if you want to use the USB ports on the display with your source system, you need to connect a separate USB cable from the display to the source system, but the U2415 only has one "upstream" port for that purpose, so you wouldn't be able to toggle USB peripherals plugged into the display between separate systems apart from physically moving that USB cable between systems as needed.  But even displays that have multiple upstream ports to facilitate that type of switching without having to move cables around don't allow data to cross over between systems.  USB doesn't quite work like that.  It's designed to connect a host device to peripheral devices, not to connect two hosts to each other.

Thank you.

So far, I've only used theU2415 for HDMI and USB to Mac MIni and on the Net. I'm considering connecting the 2nd HDMI to an air-gapped (not on Net) MacBook Pro laptop. Any leak at all in either direction via any connection must be avoided.

Thanks again

@dellmation  Understood.  There is no way to get data flowing between two different systems through a U2415.  It just doesn't have the hardware to achieve that.